On 1/30/23 14:04, Jonathan Cameron wrote:
On Mon, 30 Jan 2023 10:37:42 +0100
Mårten Lindahl <marten.lindahl@xxxxxxxx> wrote:
There are different init functions for the sensors in this driver in
which only one initialize the generic vcnl4000_lock. With commit
e21b5b1f2 ("iio: light: vcnl4000: Preserve conf bits when toggle power")
the vcnl4040 sensor started to depend on the lock, but it was missed to
initialize it in vcnl4040's init function. This has not been visible
until we run lockdep on it:
DEBUG_LOCKS_WARN_ON(lock->magic != lock)
WARNING: CPU: 1 PID: 8800 at kernel/locking/mutex.c:575 __mutex_lock+0x4f8/0x890
...
Call trace:
__mutex_lock
mutex_lock_nested
vcnl4200_set_power_state
vcnl4200_init
vcnl4000_probe
i2c_device_probe
really_probe
__driver_probe_device
driver_probe_device
__driver_attach
bus_for_each_dev
driver_attach
bus_add_driver
driver_register
i2c_register_driver
vcnl4000_driver_init
do_one_initcall
do_init_module
load_module
__do_sys_finit_module
...
Fix this by adding mutex_init on the lock in the init function used for
vcnl4040.
Fixes: e21b5b1f2 ("iio: light: vcnl4000: Preserve conf bits when toggle power")
Signed-off-by: Mårten Lindahl <marten.lindahl@xxxxxxxx>
Perhaps better to pull the lock out of the device specific setup?
Hi Jonathan!
Ok, having a
static DEFINE_MUTEX(vcnl4000_lock);
will make sure initializing it wont be forgotten for specific setups.
I'll test it.
Kind regards
Mårten
---
drivers/iio/light/vcnl4000.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/iio/light/vcnl4000.c b/drivers/iio/light/vcnl4000.c
index cc1a2062e76d..a8a9fc3b1a02 100644
--- a/drivers/iio/light/vcnl4000.c
+++ b/drivers/iio/light/vcnl4000.c
@@ -316,6 +316,7 @@ static int vcnl4200_init(struct vcnl4000_data *data)
}
mutex_init(&data->vcnl4200_al.lock);
mutex_init(&data->vcnl4200_ps.lock);
+ mutex_init(&data->vcnl4000_lock);
ret = data->chip_spec->set_power_state(data, true);
if (ret < 0)
